Sealing device for piston and cylinder assemblies



y 6, 1952 J. B. PARSONS 2,595,878

SEALING DEVICE FOR PISTON AND CYLINDER ASSEMBLIES Filed July 5, 948

INVENTOR. JUHN E. PAHSUNS 02M, ARM,

ATTK

Patented May 6, 1952 UNITED STATES PATENT OFFICE SEALING DEVICE FOR PISTON AND CYLINDER ASSEMBLIES.

John 8.. Parsons, Toledo, Ohio Application July 3-, 1948, Serial No. 36,977

4 Claims.

1 This invention relates to piston rod sealing devices, and an object is to produce a simple and eflicient piston rod sealing device associated with the cylinder in which the piston reciprocates and which is adapted to enable the egress of fluid from the cylinder during the movement of the piston in one direction but whichmilitates against the ingress of fluid to the cylinder upon movement of the piston in the opposite direction.

For purpose of illustration but not of limitation, an embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a fragmentary elevation, partly in section, of a piston and cylinder assembly showing the sealing device;

Figure 2 is a fragmentary sectional view showing the operation of the sealing device upon movement of the piston toward it for exhausting or forcing fluid from the cylinder to the outside through the sealing device;

Figure 3 is a perspective view of the felt packing forming part of the sealing device; and

Figure 4 is a perspective view of the rubberlike washer also forming part of the sealing devlce.

The illustrated embodiment of the invention comprises a metallic cylinder which is closed at its lower end by a cap H, and reciprocable within the cylinder is a piston l2 having a piston rod l3. At the opposite or upper end of the cylinder is a metallic disc I4, the end portion of the cylinder being crimped over as indicated at l5, to hold the disc in place. The disc [4 has a central aperture [6 through which the piston rod 13 passes, and bearing against the upper side of the disc I4 is a flange I! of an annular cup I8, the upper end of which is reduced into nozzle-like form IQ for slidably embracing the piston rod l3. The crimped-over end also engages the edge portion of the flange ll to hold it securely in place.

Bearing against the upper side of the metallic "disc [4 is a washer 20 of rubber or other suitable resilient and flexible material. The aperture in the washer 20 is such as snugly to fit the piston rod I3 which has a wiping action along the rod during its reciprocation. Filling the remainder of the cup 3 is an annulus 2| of felt or similar material, which is compressed in order intimately to engage the piston rod [3 and also exert a yielding pressure against the upper side of the rubber washer 20. Although felt is suitable for the purpose, any similar material may be used which is of a compressible and somewhat resilient nature. Preferably the annulus 2| is impregnated with 7 2 a lubricant to facilitate the reciprocatory movement of the piston rod 13.

In operation, when the piston l2 moves upwardly in the cylinder [0, any fluid therein such as air or water, will be forced upwardly and the pressure generated will cause the rubber-like washer to move upwardly away from the disc l4, substantially as indicated in Figure 2; the fluid either passing through the felt annulus 2| or between the annulus and the inner walls of the cup l8 and thus finds its way to the outside. the downward movement of the piston l2, a suction or partial vacuum is created above the piston causing the rubber-like washer 20 to abut against the rigid metallic disc [4 and thus militate against the ingress of fluid to the inside of the cylinder. Thus the washer 20, in cooperation with the felt annulus 2i and the metallic disc I4, during the reciprocatory movement of the piston I2, operates automatically to expel fluid from the inside of the cylinder above the piston but militates against fluid entering the cylinder.

From the above, it will be apparent that air or moisture from the outside are definitely prevented from entering the cylinder and any air or moisture within the cylinder are expelled during the reciprocatory action of th piston. In this manner, rusting of the inside of the cylinder is prevented and its life and usefulness accordingly enhanced. A structure of this character is particularly advantageous when the piston and cylinder assembly is employed in connection with the raising and lowering of windows of automobiles where the apparatus is not operated constantly but rather is employed intermittently to accomplish the desired result. Since the automobile, in the main, is out of doors, and exposed to weather conditions including rain and snow, it is important that a sealing device of this character be employed. Otherwise, rusting of the inside of the cylinder will take place and not only interfere with the reciprocating movement of the piston but shorten the Working life of the parts.

It is to be understood that numerous changes in details of construction, arrangement and operation may be efiected' without departing from the spirit of the invention especially as defined in the appended claims.

What I claim is:

1. Valve seal device for piston and cylinder assemblies in which the piston rod reciprocates through a closed end of the cylinder, said device comprising a relatively rigid disc member at one end of the cylinder and through which the piston rod reciprocates, a centrally apertured rubber- Upon like washer abutting the outer side of said member and sealingly embracing the rod, a cap at one side of the washer-like member and apertured to accommodate the rod, said washer and cup defining a space for the escape of fluids around the periphery of the washer, and compressible porous material within said cup for embracin the rod and yieldingly holding the washer against the disc member whereby movement of the piston toward said washer generates pressure slightly to shift the washer against the compressible material and allow escape of fluid from the cylinder and movement of the piston in the opposite direction creates a partial vacuum within the cylinder to hold the washer tightly against the member and militate against the ingress of fluid to the cylinder.

2. Valve seal device for piston, piston rod and cylinder assemblies comprising a rubber-like washer having a central opening of such size as to have wiping action with the piston rod reciprocating therethrough and sealing by embracing same, resilient pressure means bearing against one side of said washer, a cup-like enclosure for said pressure means and providing an opening loosely to receive the piston rod for permitting the passage of fluids, there being a venting passage between said cup-lik enclosure and the outer periphery of said washer, a substantially rigid backing for the opposite side of said washer, said backing being imperforate except for an opening through which the piston rod passes whereby the pressure means and washer yield upon movement of the piston in one direction and in response to generated positive pressure to vent fluids and the washer seats firmly against the backing in response to negative pressure to militate against reverse flow of fluids upon movement of the piston in the opposite direction.

3. A sealing structure as claimed in claim 1, in which the compressible porous material comprises felt.

4. A sealing structure as claimed in claim 1, in which the compressible porous material comprises an annulus of lubricant impregnated felt.

JOHN B. PARSONS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,964,063 Kagi June 26, 1934 2,132,035 Leipold Oct. 4, 1938 

